1. Field of the Invention
The present invention relates to a computer user interface for a digital microform imaging apparatus and more specifically to a method and apparatus that facilitates word searching on real time microform images and that highlights instances of search words on a display when located.
2. Description of the Related Art
Microform images are useful in archiving a variety of documents or records by photographically reducing and recording the document in a film format. Examples of typical microform image formats include microfilm/microfiche, aperture cards, jackets, 16 mm or 35 mm film roll film, cartridge film and other micro opaques. For example, a microfiche article is a known form of graphic data presentation wherein a number of pages or images are photographically reproduced on a single “card” of microfiche film (such as a card of 3×5 inches to 4×6 inches, for example). A large number of pages (up to a thousand or so) may be photographically formed in an orthogonal array on a single microfiche card of photographic film. The microfiche film may then be placed in an optical reader and moved over an optical projection path of a film reader until a selected page is in the optical projection path. The reader generates an image of the selected page which is then presented on an imager screen for viewing. Although other electronic, magnetic or optical imaging and storage techniques and media are available, there exists an extensive legacy of film type records storing the likes of newspapers and other print media, business records, government records, genealogical records, and the like.
Early microform readers included a projection type system that projected light through the film and on to a screen as well as optics to adjust the magnification of the images generated on the screen. To obtain a copy of an image, at least some of these systems were equipped with printers that would print hard copies of any images required. More recently, digital microform imaging apparatus (DMIA) have been developed that include an imaging sensor as well as optics for focusing film images onto the sensor. The sensor generates a digital bitmap image of the segment of the film in the optical projection path of the reader and provides the bitmap image to a desktop computer. The computer uses the bitmap image to drive a display thereby generating a digital image of the film segment for viewing by a user. The computer can be used to manipulate the bitmap image in many different ways including zooming in and out on the image, rotating the image, changing image contrast, annotating the image, etc. In addition, because the image is in a digital format, the image can be stored for subsequent access in a non-volatile memory.
The typical way microform systems are used is that a person that needs to locate information that may be stored on a microform medium identifies one or more microform storage medium (e.g., a microfilm roll) that may include the information being sought and loads the storage medium onto a microform imaging machine. The user then attempts to determine which section of the storage medium may include the information sought and aligns that segment of the storage medium with the optical projection path to generate an image on a display. The user reads/examines the imaged segment or at least a portion thereof in an attempt to find the information sought. More often than not the information sought is not located in the imaged segment and therefore the user moves on to a different segment of the storage medium or to another storage medium without storing or printing out an image of the segment. Once sought information is located in a segment, the user may either print out or store or both print and store the segment image for subsequent access. Thus, in most cases, while a microform imager user may examine a large number of microform segments, the user will only store or print a relatively small number of the segments for subsequent access.
In any medium in which most information is expressed in printed words, searching tasks are greatly expedited if word searching can be automated. For instance, in the case of a 1000 page Microsoft Word document where one segment of the document discusses Alexander Hamilton's relationship with George Washington during the Revolutionary War, for a person unfamiliar with the layout of the document and in need of locating the segment discussing Hamilton, automated word search capability where a computer processor can locate each instance of the name “Alexander Hamilton” in the document is invaluable. In the case of a Word document or the like, the stored document takes the form of a set of ASCII (American Standard Code for Information Interchange) characters, one for each character (i.e., letter, number, space, etc.) in the document. To search for a word, a processor simply compares an ASCII character set representing the word with characters in the document and identifies instances of matches. Thereafter, the processor may highlight the space around each character in a matched word for a user to see via a computer output display screen.
In the case of a bitmap image like a PDF (Portable Document Format), one way to search for words in the document is to perform an Optical Character Recognition (OCR) process on the document prior to the word search process to convert the PDF bitmap image into an ASCII type document (hereinafter “an OCR processed document”). After an OCR processed document has been generated and stored, a word search is performed in the usual manner by comparing an ASCII character set that represents a word to be searched with ASCII characters in the document to locate instances of the word.
One other way to search for words in a PDF or other bitmap type document is described in U.S. Pat. No. 5,687,253 (Hereinafter the '253 patent”). The '253 patent describes a word search process that is based on word shapes as opposed to the results of a prior OCR process. To this end, the '253 patent describes that a bitmap document image can be processed to generate a word shape for each word in the document and then the word shapes of known words from a dictionary can be compared to the word shapes of the words in the document.
While several advantages are associated with word searching capabilities in images that include text, there is no known microform imaging system that facilitates word searching capabilities of any images, much less real time images generated by an imaging system.